Abstract
Purpose: :
While 71% of Electrophysiology labs perform ERGs exclusively utilizing corneal ERG electrodes of their equivalent, 29% of labs perform skin ERGs exclusively or some of the time3. However, reliability and validity of skin ERGs have not been established in a patient population.
Methods: :
To assess skin ERGs, the charts of 100 patients who had successive skin and corneal (JET electrode) ERGs performed during the same ERG session were analyzed for test-retest reliability and validity. B-wave amplitude and latency were assessed for light-adapted ERGs (achromatic and pure cone flicker) and for dark-adapted ERGs (rod-only and maximum rod + cone response).
Results: :
The test-retest reliability of corneal and skin ERGs were highly significant (p<.0001 or less). For the corneal ERG, reliability ranged from .767 to .988, depending on condition. For skin ERGs, reliability ranged from .852 to .971. Direct comparison of skin to corneal ERGs revealed highly significant correlations for all conditions (p<.0001 or less) and ranged from .43 to .85. However, skin ERGs were found to be less sensitive than the corneal ERGs, based on linear regression analysis, sensitivity and specificity measures.
Keywords: electroretinography: clinical • electrophysiology: clinical